This invention generally relates to frame construction for portal openings including, e.g. doors and windows through exterior walls and, more particularly, to means in such frames to accommodate drainage of water during extreme weather conditions.
In doors and windows of exterior walls which have moveable panels or sashes to permit passage of air or for ingress and egress, rainfall, particularly when driven by heavy wind, will seep in and around the perimeter of the movable panels and collect within the frame. In the absence of continued rain accompanied by wind, the collected water can run out of one or more drain holes. However, a combination of the weather conditions which cause the water collection may prevent drainage, particularly where such weather conditions are persisting. More specifically, the wind pressure which drives rain water around the sash of a window is also capable of opposing the normal drainage from the window. In fact, the drainage arrangement itself may serve as an additional avenue for water to accumulate in the sill. such as accumulation of water, particularly if occurring at frequent intervals or for sustained periods, will damage the material of the frame.
One prior art arrangement designed to combat this problem utilizes a sill of special construction wherein a valve is utilized to close a drain hole in response to wind pressure. This arrangement is unsatisfactory for a number of reasons. Initially it is recognized that such construction adds to the cost of the window. Secondly the incorporation of the valve structure increases the size of the window. Thus, doors or windows having standard pane sizes will have non-standard, oversized frames. Therefore, not only is the material cost of the door or window increased, the cost of installation increases because the craftman must accommodate the non-standard frame sizes. Anyone remotely skilled in these arts recognizes the difficulties encountered in the building trades with non-standard components.